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Binding Checkbox to nchar column
Message
 
 
To
26/01/2010 12:06:05
General information
Forum:
ASP.NET
Category:
Forms
Environment versions
Environment:
C# 2.0
Miscellaneous
Thread ID:
01445996
Message ID:
01446004
Views:
35
Hi Bonnie,

Thank you for the answer and for the code. I do have a checkbox subclass but no code there (just a "shell"). So I will use your suggested code. And as Borislav suggested, I may change this column to a bit type (to simplify things) but in the future may need a more complex checkbox binding.

I appreciate your help!

>Hi Dmitry,
>
>Do you have a checkbox subclass? You'll need one. In fact, I have two checkboxes, one for binding to normal bool values and one for binding to string values. Your code might have to be slightly different, since you're utilizing a BindingSource and my examples below bind directly to the DataTable rather than to a BindingSource (you could simply add another overloaded DataBind() method):
>
>This CheckBox binds directly to your DataColumn rather than an intermediary property (which can be done too, but takes more code IMHO). This class can be extended to be able to used with other strings, such as T/F, but I’ll leave that as an exercise for the reader:
>
>
>public class BBCheckBoxString : System.Windows.Forms.CheckBox
>{
>	protected Binding oBinding = null;
>
>	public virtual void DataBind(System.Data.DataTable Data, string Column)
>	{
>		this.Checked = false;
>		this.oBinding = new Binding("Checked", Data, Column);
>
>		this.oBinding.Format += new ConvertEventHandler(this.FormatHandler);
>		this.oBinding.Parse += new ConvertEventHandler(this.ParseHandler);
>
>		this.DataBindings.Add(this.oBinding);
>	}
>	protected override void FormatHandler(object sender, ConvertEventArgs e)
>	{
>		if (e.Value.ToString() == "Y")
>			e.Value = true;
>		else
>			e.Value = false;
>	}
>	protected override void ParseHandler(object sender, ConvertEventArgs e)
>	{
>		if ((bool)e.Value == true)
>			e.Value = "Y";
>		else
>			e.Value = "N";
>	}
>}
>
>
>Then, on your Form or control, to databind that Checkbox, you’d do this:
>
>
>this.MyCheckBox.DataBind(MyTable, "MyYNColumn");
>
>
>Now, a regular CheckBox:
>
>
>public class BBCheckBox : System.Windows.Forms.CheckBox
>{
>	#region Declarations
>	protected Binding oBinding = null;
>	protected CurrencyManager oCurrency = null;
>	protected DataTable m_BoundTable = null;
>	protected string m_BoundColumn = "";
>	protected bool m_ReadOnly = false;
>	#endregion
>
>	#region Methods
>	public virtual void DataBind(System.Data.DataTable Data, string column)
>	{
>		this.Checked = false;
>
>		this.m_BoundTable = Data;
>		this.m_BoundColumn = column;
>		this.oBinding = new Binding("Checked", Data, column);
>
>		this.oBinding.Format += new ConvertEventHandler(this.FormatHandler);
>		this.oBinding.Parse += new ConvertEventHandler(this.ParseHandler);
>
>		this.DataBindings.Add(this.oBinding);
>
>		if (this.BindingContext != null)
>		{
>			this.oCurrency = (CurrencyManager)this.BindingContext[this.oBinding.DataSource];
>			this.oCurrency.PositionChanged += new EventHandler(this.PositionChangedHandler);
>		}
>
>		this.SetEOF();
>	}
>	protected virtual void SetEOF()
>	{
>		if (this.oCurrency == null)
>			return;
>
>		if (this.oCurrency.Position < 0)
>			this.Enabled = false;
>		else 
>			this.Enabled = !this.ReadOnly;
>	}
>	#endregion
>
>	#region Events
>	protected virtual void FormatHandler(object sender, ConvertEventArgs e)
>	{
>		if (e.Value == System.DBNull.Value)
>			e.Value = false;
>	}
>	protected virtual void ParseHandler(object sender, ConvertEventArgs e)
>	{
>	}
>	protected virtual void PositionChangedHandler(object sender, System.EventArgs e)
>	{
>		this.SetEOF();
>	}
>	
>	#endregion
>
>	#region Properties
>	[DefaultValue(false)]
>	public bool ReadOnly
>	{
>		get { return this.m_ReadOnly; }
>		set 
>		{ 
>			this.m_ReadOnly = value; 
>			this.Enabled = !value;
>		}
>	}
>
>	#endregion
>}
>
>
>HTH,
>~~Bonnie
>
>
>>Hi,
>>
>>I have a column in a table of type nchar(1). The value in this column is "A" or "I". I want to bind this column to a check box and show in the caption of the check box "Active" (for 'A') and "Inactive" for 'I'
>>
>>I tried the following binding code but get error:
>>
>>
>>this.chkStatus.DataBindings.Add("Checked", bindingSource1, "Status=='A'");
>>
>>
>>What am I doing wrong? TIA.
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